0x0052 SSUTR2 CPC (Call Processing Control)
0x0053 SSUTR2 SPRC (Signaling Procedure Control)
0x0054 SSUTR2 BLR (Blocking/Unblocking Signal Reception)
0x0055 SSUTR2 BLS (Blocking/Unblocking Signal Sending)
0x0057 SSUTR2 CRI (Continuity Recheck Incoming)
0x0058 SSUTR2 CRS (Circuit Reset Sending)
0x007C SSUTR2 CRO (Continuity Recheck Outgoing)